Question for PE and Simon, others?

Discussion in 'Silver Gelatin Based Emulsion Making & Coating' started by Paul Verizzo, Jul 5, 2008.

  1. Paul Verizzo

    Paul Verizzo Member

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    OK, this question has been burning for decades. Maybe you can help the itching...

    Just how the heck is film coated; so thin, so consistent, multiple layers even? And all in the dark for pan and color films!

    I'd ask for pictures but then I guess the lights would be on........ :rolleyes:
     
  2. Ian Grant

    Ian Grant Subscriber

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  3. Paul Verizzo

    Paul Verizzo Member

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    Thanks, pictures of machines, but how?
     
  4. Photo Engineer

    Photo Engineer Subscriber

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    There is a complete thread with pictures here: http://www.apug.org/forums/forum205/45479-film-coating-machine-homemade-flickr.html

    How is it done? There are 3 basic methods in use today and 3 more that have been mostly abandoned except by 3rd tier companies.

    The three modern methods include extrusion of gelatin emulsion onto support as shown in that thread, and by slide or curtain coating. It is all described in US Patent 2, 761, 791 granted to T. A. Russell of Kodak.

    PE